Air-valve



(No Model.)

. G. M. DAVIS.

AIR VALVE.

No. 404,963. Patented June 11, 1889.

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UNITED STATES PATENT OFFIC GEORGE M. DAVIS, OF CHICAGO, ILLINOIS.

AIR-VALVE.

SPECIFICATION forming part of Letters Patent No; 404,963, dated June 11, 1889. 7 Application filed March 8, 1889- Serial No. 302,439. (No model.)

To all whom it may concern:

Be it known that I, GEORGE M. DAVIS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in an Air-Valve, of which the following is a full, clear, and exact description, that will enable others to make and use the same, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates more especially to the class of air-valves used on radiators in the system of steam-heating for the purpose of allowing the air to escape and to trap the steam. The valve may be set to act automatically or be adjusted by hand and Worked on the expansion principle.

Figure 1 is a longitudinal section showing the device inserted in a radiator pipe or tube 5 Fig. 2, a transverse section in plane 2, Fig. 1; and Fig. 3 a side elevation of the expansionstem, the screw-threaded adjusting-head be ing shown in section.

Referring to the drawings, A may represent a steam-radiator; B, the expansion-valve tube, and O the expansion-stem inserted in the expansion-tube. The valve-tube is composed of metal and is provided with the enlarged mouth end at, having the screwthreaded interior a for the reception of the correspondingly-threaded head a of the ex pansion-stem.

The tube B is provided exteriorlywith the threaded part a and screws into the radiator at that point, the expanding part proper of the tube extending into the radiator, as shown. The expansion end of the valve-tube is provided with the small aperture a ,through which the air, expelled from the radiator, passes into said tube and finally escapes into the outer atmosphere through the vent-opening a leading out from the chamber a.

The expansion-stem will be composed ordinarily of vulcanite or of some suitable composition, of which rubber is the principle ingredient. This stem is provided longitudinally with a number of grooves 19, to facilitate the escape of the air forced out by the pressure of steam, as the stem will usually be made close-fitting in the tube, leaving but a small annular space between the two, so that the greatest expansion of the stem will be endwise. The inner end of the expansion-tube presents the convex seat to the seating end of the expansion-stem inclosing the aperture a. By properly adjusting the expansionstem with reference to the seating end of the tube the air-escape passage will be automatically opened and closed by contraction and expansion. The expansion-tube extending directly into the radiator receives the direct heat of the steam and has a more sensitive and positive action and thereby prevents any of the products of condensation from escaping through the air-valve. The arrangement is simple and convenient, and only as much of the surface of the expansion-stem is exposed to the direct contact of the steam as equals the area of the aperture in the end of the tube, thus greatly increasing the dura bility of these parts.

When the rubber stem has become worn, it can be easily replaced by another without the least inconvenience. The valve can be opened also and closed by hand when necessary.

The vulcanite expansion-stem and screwhead or nut may be formed integral, or the stem and head in distinct parts, as practical Working may require.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent, is

1. The combination, with a radiator, of the valve-tube projecting inside of the steamspace and provided in the inner end with an inlet-opening and exteriorly with an escapeopening, and the expansion-stem inserted in said tube and closing said inlet-opening by expansion after the cold air is expelled and uncovering the same When the steam is shut oif, substantially as and for the purpose set forth.

2. In an air-valve, the combination, with the expansion-tube project-ing inside of the radiator and having the outer enlarged monthend a threaded interiorly, and the exteriorlythreaded part d of the expansion-stem inserted in said tube and provided with the threaded head a engaging with the corretube provided longitudinally with a number spondingly-threaded mouth part, substmr of grooves and inserted in said tube, substzm- IO tially as and for the purpose set forth. tially as and for the purpose set forth.

3. I11 an air-valve, the combination, with t I i 4 I I the Vented expanslon-tube provided exte- GEORGE M DAVIS riorly with the threaded part a and having \Vitnesses:

the expansion end extending inside of the L. M. FREEMAN, stean1-space,of a radiator, and the expansion- J. B. DONALSON. 

